In order to prevent damage during transporting and storage, electronic equipment, machines, and other fragile products are usually enclosed or covered with a packing or cushioning material and placed within paper board boxes.
Typically, such packing or cushioning material have been manufactured from a synthetic resin, such as a plastic or styrene foams, which are formed to conform with the outer shape of the products to provide a protective cushion. Unfortunately, however, while plastic and styrene resin foams are light in weight and inexpensive to manufacture, their use is an environmental concern because they are not perishable and do not naturally decompose in land fills. Further, when incinerated, plastic and styrene resin foams often produce noxious gases and generate a significant degree of heat which can result in damage to the combustion facility. Accordingly, alternative packing or cushioning materials have been developed which are pollution-free, inexpensive, and relatively easy to manufacture.
One alternative material which has been found to be suitable for use as a packing or cushioning material is produced by mixing together water and paper, including virgin, recycled or waste paper, to form a fibrous pulp slurry. The fibrous pulp slurry can be molded into finished articles having contoured shapes for receiving the products to be protected. Such molded articles have relatively good shock-absorbing characteristics, are relatively inexpensive to produce in large quantities, are biodegradable, and do not produce noxious gases or generate a significant degree of heat when incinerated. Accordingly, the use of such molded articles for use as packing or cushioning material is highly desirable.
Molded articles formed from a fibrous slurry, such as a pulp slurry, are typically produced by the process of matting the slurry fibers onto one side of a forming die by first inserting the die into the slurry. A vacuum is then applied in such a manner that the water comprising the slurry passes through perforations or channels in the die thereby leaving a layer of wet fibers deposited on the die surface. After sufficient water has been drawn to obtain the required thickness of the fiber layer, the die is removed from the slurry. The formed molded article can then be removed from the forming die by various conventional means.
One problem associated with producing molded articles from a fibrous slurry is the need to prepare specimens which can be tested for their shock-absorbing characteristics. Often a molded article requires numerous design changes, each requiring the production of a test specimen, before a final configuration is selected which provides the necessary shock-absorbing protection.
Another problem associated with producing molded articles from a slurry is the need for the article manufacturer to provide potential customers with specimens having the appearance of the final production article for use in analyzing sale proposals analysis.
One conventional forming die utilized for producing molded articles from a fibrous slurry comprises a metallic or rigid plastic block having a molding surface formed by machining or electroforming techniques to the same contoured shape as the finished article. A plurality of perforations are typically drilled through the molding surface to permit the passage of air and water during molding operations.
Another conventional forming die utilized for molding packing or cushioning articles from a fibrous slurry comprises a porous block formed from ceramic or glass beads bonded together by a resin within a master mold configured for producing a forming mold having molding surfaces with the same contoured shape as the finished article.
Unfortunately, however, while such conventional forming dies are capable of manufacturing quantities of molded articles from a fibrous slurry, their manufacture requires relatively labor intensive, time consuming, and expensive pattern making, molding, machining and drilling, or electroforming operations. Accordingly, a common problem among conventional forming dies for forming molded articles from a fibrous slurry is the inability of producing specimens for testing in a relatively short amount of time and with relatively little expense. Therefore, a need exist for a method and apparatus for producing molded articles from a fibrous slurry, which can be utilized to provide specimens for testing and evaluation in a relatively little time and with little expense.